Translucent picture-projection screen.



J. F. R. THOEGER. TRANSLUCENT PICTURE PROJECTION SCREEN.

MPLICATION FILED/ DEC. 24, |913.

PafentedAug. 24, 1915.

Wl TNE SSE S vJOHN E. EoBEE'r TRoEGER,. oE NEW YonK, N; s z.

TEANsLUcENT PICTURE-PROJECTION SCREEN.

-Specifcation of Letters Patent. Patgnted Aug, 24, 1915.

i Application led 'December 24, 1913. Serial N0. 808,546.

.and ruseful Improvements in Translucentl Picture-Projection Screens, o f which the following' isa specification. Y

l This inventlon relates to translucent exh1 m1xed together forming a dough-like subbition screens for projecting machines.` The principal object of the invention is to provide a Composition for screens of this character giving. the required degree of.

translucency, strength, flexibility and water and fire resisting properties.

In the accompanying drawing, Figure l is an elevation, and Fig.V 2 1sv a fragmental detail perspective view illustrating the structure of the screen formed of the composition 1 according to my process.

In carrying out my process to produce the improved composition, I take four parts of fgelatinous or gummy substance such, as" gelatin or glue and add to thesame two parts of glycerin and two parts of formalde-l hyde and'boil until water is driven ofi' when `a dough-like mass remains `which mavbe y rolled into sheets. The latter, whileustill soft, may be run over with a corrugated roller, which imparts to the surface of the sheet longitudinal corrugations or ridges.

-. hot room at about 100 Ff humidity and also renders .it reproof.- Thus, thescreen may be used in the openV air and not be affected by the elements and is also safe as a fire risk. Referring to the drawing, the sheet 10 is illustrated as formed with the wavy corruf' gations or ridges 11. When itis desired to reinforce the sheet to make it stronger, .I

preferably stretch a mesh of ibrous strands of a suitable strong substantial but translu#y cent material 12, such as silk or the like and place the .mesh vor web over the sheet while the latter is still soft. The' fibers may then be embedded in the sheet by passing the same into the soft material.A If desired, a roller may be passed over so as to more completely embed the fibers and to smooth and compact the surface of the sheet into which" the fibers 4have been embedded. To further increase the weather resisting properties as well as durability of the screen, I may coat the same with a thin coating of a translucent tough flexible weather resisting compound. This compound is preferably formed as"follows':/Ten parts of air dried i.

1 white soap and ten parts of alum are dissolvedfseparately in water, boiled separately,

stance consisting of stearate, palmitate or oleate of aluminum, and then the water is entirely expressed and the residue perfectly dried. 'The latter is then dissolved in thirty parts of benzin and intothissolution the sheet prepared as previously set forth is ydipped and then dried. The benzin quickly evaporates leaving ahard tough ex'ible `weather resisting lm or coating which entirely envelops the sheet and protects the same from the action of the elements. Also it has been found by actual experiment that through this coating and the screen asa whole the color tones and tints of the picture are displayed to the best advantage from an artistic standpoint when a colored picture is projected. At the\same time it softens the light so as tol obviate any fatigue to the eyes of the spectators. L

When the enveloping protective coating above described is used, the formaldehyde may if desired be omitted without sacrificing materially the advantages arising from my improved composition.

it will be understood/@hat I do not desire to be limited bythe exact proportions ofthe ingredients above given as these may be varied without' departing from the spirit of Ymy invention.`

Having thus described my invention, I

claim as new and desire .to secure by Letters Patent: J

y1. A translucent .sheet for translucent screens for projecting machines consisting of a base consisting of a gelatinous or gummy substance, andan agent for imparting flexibility thereto, and a layer of tough translucent waterproof-coating enveloping 2. A translucent sheetI for translucent screens for projecting machines consisting of a gelatinous or gummy base, an agent to render the same fire-proof, and an exterior translucent waterproof coating covering the v3. A `'translucent' sheet for translucent screens for projecting machines consisting of a base of gelatin and glycerin, and a surface coating for the base lconsisting cfa' saponaceous compound of'aluminum.

,4. A translucent sheet for translucent 1c screens for projecting machines consisting of a base formed of tWo parts of gelatin and one part of glycerin, and a surface coating consisting of a saponaceous compound of aluminum.

part of glycerin and one part of formaldey hyde, and a translucent surface coating consisting of a saponaceous'compound of aluminum. l

Signed at New York city, in the county of New York, and State of News7 York, this 19th day of December A. D. 1913.

JOHN F. ROBERT TROEGER. Witnesses:

WM. I. COHEN, GEO. B. HALBUT. 

